Machine for bending sh eet metal



(No Model.) Y 2 Sheets-Sheet; 1 L. GOBURN.

MACHINE FOR BENDING SHEET METAL.

(No Model.) 2 Sheets-Sheet. 2.

- L. COBURN.

MACHINE POR BBNDING SHEET METAL.

No. 390,346. Y Patented 001:. 2, 1888.

1 y [HW lm Z-Emue] 505111127.

LFJMUEL COBURN, OF HOLYOKE, MASSACHUSETTS.

MACHINE FOR BENDNG SHEET METAL.

5:13113CIPICATIONV forming part of Letters Patent No. 390,346, dated October 2, 1888. Application filed Fehruaryl, 1888. Serial No. 263,606. (No model.)

To @,ZZ whom it may conceive:

Beit known that I, LEMUEL Colmo-1N, a citizen of the United States of America, residing at Holyoke, in the county of Hampden and State of Massachusetts, have invented new and useful Improvements in Machines for .Bending Sheet Metal, of which the following is a specitication.

This invention relates to machines for bending metal in parallel longitudinal folds; and it is particularly-applicable for use in the manufacture of trolley-tracks, such as are illustrated and described in Letters Patent of the United States granted to me June 2l, 1887, No. 365, 21,0, but, as will appear from the descriplion hereinafter' given,it embraces certain constructions and contrivances common to and applicable in machines for bending metal for other purposes; and the invention consists in the constructions and combinations of parts, as will hereinafter fully appear and be set forth in the claims.

In the accompanying sheets of drawings, Figure 1 represents in side elevation and partial central longitudinal vertical section a machine for bending fiat strips of sheet metal into the form desired and suitable for trolley` tracks; and Fig. 2 is a plan view of the lower portion there0f,which is below the plane indicated by linee fu, Fig. 1. Fig. 3 represents an enlarged detail view in horizontal section on line w w, Fig. 1. Fig. 4 representsinperspective and enlarged a section of a sheet-metal trolley-track, such as may be formed under the operation of the present improved sheetinetal-bending machine. Figs. 5, G, and 7 are enlarged vertical cross-sectional views of the die portions of the machine respectively on lines w ai, y y, and of Figs. 1 and 2, there also being indicated thereupon or in relation thereto the cross-section of a strip of sheet metal in the various phases thereof which it possesses or is made to possess under the action ofthe various parts of the machine. Fig. S is an enlarged vicw,in perspective,of a portion of the length of the draft or hook rod, to be hereinafter referred to; and Fig. 9 is a perspective view of astrip or blank ofsheet metal Aof a form suitable for the production of the trolley-track.

The present machine comprises three sets of portion, within or upon ,which thesheet-metal strip is disposed, and the upper portion forming or attached to a vertically-reciprocating plunger, and the several die parts are ranged and aligned longitudinally, as shown.

As to the set of dies A, (see Fig. 5,) the purpose of which is to convert the sheet-metal strip from the flat form shown in Fig. 9 into the U forni indicated by dotted lines, Fig. 5, and the black cross-section, Fig. of, the lower or female die, a, thereof consists of a longitudinal metal trough,of substantially U shape in crosssection, with its opposite walls for a portion of its height vertical, as shown, and thence preferably outwardly daring, as seen at b, and at the upper edge of each flaring side wall horizontal wings or shelves c may be provided, and the upper or male die of this set of l.

dies is transversely of rectangular form, as shown.

The set of dies B, (see Fig. 6,) which is for converting the U or trough-formed strip into the form of a tube with transversely-rectangular walls,.as indicated by dotted lines in said figure, and the black cross-section,Fig. 7, as to its lower die, consists or" a longitudinal troughshaped body, d, having horizontal bottom and vertical side walls, c, with converging upper edges, f, within which is disposed a parallel core or wrapping-bar, g, and the upper die, h, of said set of dies Bis on its Linder side formed with ahorizontal central portion, fi, and downwardly and outwardly diver-ging cxtensionsj, as shown, said horizontal portion i being of a width about equal to the distance between the side walls of the U-strip of metal which is to surround the core-bar g, and said Haring eX- tensionsj being formed to lie, when said upper die is down, outside of the converging and inclined edges f of the trough-body of the lower die. v

The set of dies C, (see Fig. 7,) which is for converting the rectangular tubular strip, as seen in the black cross-section, Fig. 7, to the form indicated in said ligure by dotted lines, and as seen in Fig. 4L, as to its lower die, o, consists of a substantially rectangular troughshaped body,with the upper inner edges, k, of its side walls curved inwardly, as shown, within which is disposed a parallel core-bar, in, of similar shape and size tothe core-bar g of the die B, but having in its upper side a longitudi- IOO nally-extending depression or recess,l, and the upper die, a, ot' said set of dies C is provided with a downwardlyextending longitudinallyM arranged rib, p, exteriorly corresponding to the walls of the depression Z in said eore-bar m.

The longitudinally-aligned lower dies,a d o, have in their bottom surfaces a groove, q, eX- tending continuously therethrouglnand within which is placed a draft-rod, D, adapted for a baek-andAforth endwise play therein. Said draftrod at its rear end is provided with a rigid hook or dog, r, and intermediate of its length it is provided with pivoted dogs s s, having bearings within recesses t ofthe draftbar, said pivoted dogs being weighted at their rear ends, so that normally their forward ends or noses, a, stand above the upper side ofsaid draft-bar, and said dogs are so adjusted on the draft-bar that when the bar is in its normal position, as seen in Figs. 1 and 2, the said dogs r s s will stand in positions back of and against the rear ends ot' the central bottom portions of the sheet-metal strips when in their respective places in the lower dies of the diesets A, B, and C, as occu rs in the operation of the present machine; and said draft-rod D at its forward end is provided with a cross-head, 10, and a ring-eye, 11, and to the said crosshead one end ofa rope, 12, is attached,which passes rearwardly around a sheave, 13,thence forward to and around a drum, 14, and rearward to an engagement with said ring-eye 11 of the draft-bar, as shown in Fig. 1.

The bottom faces of the core-bars g m are longitudinally recessed, as at 15, to permit the passage of the dogs s s in the forward movement of the draft-rod, it .being understood that in the return movement of said draftrod said dogs are depressed below the upper surface of the draft-rod when passing under stri ps of metal in the trough-bodies d o, through which they travel.

rlhe side walls, 1G 17, of the trough-bodies ofthe lower dies of the sets of dies B C are formed of wedge shape or tapering in their length, as seen in Fig. 2, and said side walls are intended to be drawn out ashort distance, lthereby widening the spaces between said side walls and the core-bars, releasing the bind upon the metal formed thereat, and the corebar m ofthe lower die ofthe set C is made in two parts-an upper part, 18, and lower part, 19 each tapering as to vertical thickness, as shown in Fig. 1, so that when the upper portion, 1S, is drawn endwise forward the height of the core-bar m is decreased, permitting a release from vertical bind of said bar upon the sheet-metal strip folded thereabout, as shown. The lower portion, 19, ofsaid core-bar m is jointed to the core-barg in any suitable manner -for instance, halved together77 therewith, as seen at 20,Fig. 1; and said wedge shaped side walls, 16 17, are also jointed to move n unison and foreonvenient endwise of one ofthe uprights, E, of the machine, the said lever 21 by its lower slotted end engaging a pin of the wedge-wall 17,and the lever 2 by its lower slotted end engaging a pin of the movable tapering part 18 of core-bar m. The said core-bar g at its rear end is suspended a slight distance above the bottom of thetroughbody of the lower die of the set B by the engagement therewith ofa vertical bolt, 25, projeeting upwardly and loosely through an aperture, 26, ofahorizontal web,27, ofthe branched base of one ofthe uprights,E, said bolt being surrounded between its head and said web by a stitf spiral spring, 29. The vertical position of said suspended end ofthe core-bar g is adjusted by the interposition ot' the washers 28 about said bolt between the upperside ofsaid bar g and the lower side ofthe web 27.

The male die of the set of dies A is provided at its under face near each end with vertical downwardly-tapering pins 30 in central longitudinal alignment, which are for the pur pose of entering the centrally-aligned holes 31 in the blank G of sheet metal to be bent for maintaining it cent-rally in the die for a uniform and symmetrical bending, and the draftbar D has holes 32 to permit the entrance therein of said centering-pins 30.

As will be particularly seen on reference to Figs. 1 and 3, each plunger-die is formed with a vertical groove, 33, at its ends, into which a tongue, 34, of a V-edged bearing-block, F, enters, the said VAshapcd bearing-blocks playing vertically in corresponding V shaped grooves, 35, of the standards E. The tongue 34 of each V bearing-block is provided with horizontallyextending slots 36, through which bolts 37 extend, as also through the walls of the plunger-body at each side of the groove 33, said bolts being headed and provided with nuts for securing said blocks in place. The said blocks have vertical walls or shoulders 47 extending laterally beyond the faces of the tongues 34, and between said shoulders 47 and the inclined ends 38 of the plunger-bodies wedges are driven, which serve to force said blocks to a close bearing at all times. Said wedges 39 are to be retained in place bythe overlyingnuts,washers,orheads 40ofbolts41,whieh pass through the bodies of the wedgeblocks, as shown; rlhe plungers are to be raised and held and then lowered or allowed to descend in any desired or approved manner. As shown, the plungers are supported by ropes or chains 42 'from drums carried on an overhanging shaft, 43. Said plungers are intended to be raised by the rotation of said shaft, and when at the proper height be held by dogs 44, which are arranged on an oscillating shaft, 45. A spring, 4G, suitably applied tothe shaft 45, eX- erts a force to swing the said dogs into the vertical plane of travel of the plungers to support them. On an oscillation of the dog carrying shaft in the proper direction by the lever or crank 5l, said supports are removed and the plungers are allowed to descend under their own weight, their elevating-ropes 42 being al- IOC iowed to unwind from the overhead drums, which are allowed to rotate with or on the said shaft 43, some well-known form of releasing-clutch devices being preferably applied on said shaft, and so that the rotation of the shaft 45 may be limited, so that the dogs tet thereon will be normally held to and limited in their de-supporting positions. A stop, 54, is suitably lixed on the side of one end standard, E, against which the crank-lever 51., rigidly attached to and as one with said shaft, may abut, as indicated in Fig. 1.

The operation of the machine herein described is as follows: A blank sheet of metal, as G, is `first placed lengthwise on the shelves c of the lower die of the set of dies A. The plunger is then allowed to drop, forming the strip of metal iuto the U shape. lhen on raising the plunger and moving the draftrod D endwise, as described, by the engagement of the rear hook, r, .with the end of the bottom of the` U-formed strip, the latter is carried horizontally endwise and made to telescope the core-bar g of the lower die of the set B, when the draft-rod is returned to place. Then. on the descent of the plunger l1. of said set of dies B, the said U-strip is converted into the form ofatransversely-rectangular tube. Then, ou withdrawing the side wedge-walls, 16 and 17, and moving` the draft-rod forward by its intermediate dog, s, the said tubular-formed strip is carried horizontally end wise and made to telescope the core-bar m. rlhe said wedgewalls are then returned to their closed positions, and on the descent of the upper die or plunger ofthe setof dies C the meeting edges of the strip are turned inwardly and parallel with the side walls, as seen in Fig. 4. Then, ou sliding the wedge side walls and also the upper inclined or tapering part, 18, of corebar m, and drawing out the draft-rod D, the completed trolley-track strip is by the outer hook, s, carried outof the lower die of the set C. in practice the upper dies are all int-ended to be moved in consonance with each other, there being a sheet of metal to be bent as described, placed on or in the lower die of cach ofthe set of dies A B C.

Other means for making the side walls, 16 and 17, adj estable than by forming them with outer inclined sides, as described, may be substituted as equivalents thereof-as, for iustance, by having said separable side walls supported on and carried by screws which are suitably supported in threaded bearings and to be operated by worm-gears carried by a common shaft.

The formation of the lower die, a, of the set A with the upper outwardly-Haring walls, b, as shown, is most advantageous, as it in sures a gradual bending of the tlat sheet of metal at the time of the impact of the upper die, obviatiug the liability of any shearing action or breaking of the metal at the lines of bend, and assuring, even in the bending of inferior sheet metal, most satisfactory and practical results.

Vhat I claim as my invention is 1. In a sheet-metal-bending machine, the combination, with a longitudinal troughformed lower die having its bottom vprovided with centrally-aligned apertures, of a corresponding longitudinally-arrauged male pluugerdie provided with centrally-aligned pins 30, and guided for a play into and away from said trough-formed die, substantially as and for the purpose described.

2. in a sheet-metal-bending machine, the combination, with a female die, a, having a` horizontal bottom provided with aligned apertures and vertical side walls terminating in upwardly-liaring walls b b, of a longitudinallyarranged male plu nger-dic, substantially ot' rectangular shape in cross-section,.provided with centrally-aligned pins 30, and guided for a play into and away from said lower die, subA stantially as and for the purpose described.

3. In a Inetalbending machine, the combination, with a longitudinally-ranging female die having a longitudinal groove or way, q, and a correspondinglyformed male plungerdie, of a slide or draft rod playing in said groove and provided at its rear end with a dog or hook, r, substantially as and for the purpose described.

4. In a metal-bending machine, the combination, with a longitudinal female die having a longitudinal groove or way, (l, and a correspondingly-formcd malepluugerdie ofa slide or draft rod playing in said groove, andf provided at its rear end with a Vdog or hook, r, and a flexible connection by one end attached to the forward end of said draft-rod, thence passing to the rearward of the said forward end around a suitable guide, thence forward to and around a rotatable drum, and thence rearwardly to au engagement with said draftrod, substantially as and for the purpose described.

5. In a metal bending machine, the combination, with the die A, comprising the lower longitudinal trough part, c, having horizontal bottom and vertical side walls terminating in the upwardly-flaring walls b b, and the longitudinally-ranging male plunger-die, of the die comprising the lower lougitudinally-arranged trough part, tl, the longitudinal corebar ol' rectangular cross-section within said trough part d, and the plunger h, having horizontal bottom t', with down wardly-daring wings j, substantially as and for the purpose described. (i. In "a metal-bending machine, the combination, with the die A, comprising 'the lower longitudinal trough part, c, having horizontal bottom and vertical side walls terminating in the upwardly-Haring walls b b, and the horizontally-ranging male plunger-die, of the die B, comprising the lower longitudinally-arrauged trough part d, havi ng horizont-al bottom and vertical side walls, one of which is laterally adjust- IOO IIO

able, the longitudinal corebar oi rectangular cross-section supported withinsaid trough part il, and the plunger 71., having horizontal bottom i, anddownwardly-flaring wings y', substantially as and for the purpose described.

7. In a metal-bending machine, the combination, with a female die provided within one wall with a longitudinal groove or way, and a plunger-die of corresponding crosssection, and one or more sets of' dies comprising lower longitudinally-arranged female dies provided within one wall with a longitudinal groove or Way in continuation of said first-mentioned groove, and each provided with a longitudinal core-bar and plunger-dies, of a draft-bar, D, arranged for a slide in said continuous groove or way, provided with suitably arranged abutments, for the purpose described.

8. In a metalbending machine, a trough and a plunger-die, and one or more sets of dies comprising lower longitudinally-arranged trough portions, one or more of said trough portions being provided with a separable side wall of wedge shape, suitably guided for a lengthwise movement, and the lever 21, engaging said wedge-shaped side wall, combined with a longitudinal core-bar, substantially as and for the purpose described.

9. In a metal-bending machine, the combination, with the trough and plunger-die A, and a stationary standard or bracket, 27, provided with an aperture, 26, of the die B, comprising the longitudinally-arranged troughbody, the core barg and plnngerh, the headed bolt 25, passing through said aperture 26 and connected to the end ot' said core-bur, and the spiral spring 29 and washers 28, substantially as and for the purpose described.

10. The combination, with the trough and plungerdies A, and the die B, comprising the lower longitudinallyarranged trough-body,d, having the movable inclined side wall,16, corebar g, and plunger 7L, ofthe die C, comprising the lower longitudinally-arranged troughbody having movable side wall, 17, jointed to said movable side wall 16, core-bar m, consisting of the lower portion, 19, having its upper face inclined, and the upper portion, 18, having its lower face inclined and having the longitudinal depression Z, and the levers 21 and 22, the former engaging said inclined side wall, 17, and the latter engaging said upper coreebar portion, 18, substantially as and for the purpose described.

11. In a metal-bending machine, the combinat-ion, with uprights E, having vertical slideways 35 therein, of a plunger-die body having inclined ends 38 and vertical grooves 33 thereat, the bearingblocks F, having the shoulders 47, and tongues 34, provided with the horizontally extending slots 36, the headed bolts 37, and the wedges 39, substantially as and for the purpose described.

12. In a metal-bending machine, the combination, with uprights E, having vertical slideways 35 therein, of a plunger-die body having inclined ends 38 and vertical grooves 33 thereat, the bearing-blocks F, provided with the headed bolts 41, and having theshoulders 47 and tongues 34, provided with the horizontally-extending slots 3G, the headed bolts 37, and the wedges 39, substantially as and for the purpose described.

13. In a metal-bending machine, the combination, with suitable uprights, E, having vertical slideways therein, and one or more plunger-dies having bearings in said vertical Ways,ofa longitudinally-arranged springactuated rock-shaft, 45, provided with fixed dogs adapted to be swung into the vertical plane of 8o movement of said plunger-dies, and having the crank-lever 51 and the stop 54, substantially as and for the purpose described.

14. In a metal-bending machine, in combination, the frame or uprights E, and the die A, comprising the lower trough portion, a, having horizontal bottom and vertical side walls terminating in the upwardly-Haring eX- tensions b b, and male plunger-die,of substanti-ally rectangular cross section, having the pins 30, the die B, comprising trough-body d, having horizontal bottom and vertical side walls terminating in vinwardly-inclining portions f, one of which side walls is laterally movable, the transversely-rectangular corebar g, supported within said trough-body d, and the plunger-die h, havingl lower horizontal face, i, and downwardly-Haring wingsjj, and the die C, comprising the lower trough-body, o, having horizontal bottom and vertical side walls, one of which is laterally movable, the core-bar m, comprising lower tapering portion, 19, jointed to said core-bar g, and the upper tapering portion, 18, provided with the longitudinal depression l, and the male plunger-die u, having the rib p, the said core-bar portionsg 19 being provided on their under sides with the longitudinal way 15, and the said horizontal bottoms of said lower trough portions, a d o, having the longitudinal way q, the draft-rod D, adapted to slide in said way q, having the aligned holes 32, the rear hook, r, and the recesses t', within which are pivoted the counterweighted dogs s s, the ovcrhanging drumshaft 43, and the rope or chain supports between the drums and the plungerdies, substantially as and for the purpose described.

LEMUEL COBURN.

Witnesses:

WM. S. BELLows, G. M. CHAMBERLAIN.

ICO 

